1. Field of the Invention
This document relates to an apparatus and method for controlling an image sensor output, and more particularly, to an apparatus and method for enabling the output of an image sensor, such as a charge coupled device (CCD), to be varied in accordance with a user-defined number of valid pixels.
2. Discussion of the Related Art
Generally, a camera that shoots still or moving pictures uses an image sensor such as a CCD.
A CCD has a fixed number of pixels. Generally, the image resolution varies with the number of pixels in the CCD. For example, a CCD with 2M (Mega) pixels generally can output a high resolution image of 1920×1080, while a CCD with fewer pixels can output a lower resolution image.
In a conventional camera, when it is desired to vary the resolution of an image output from the CCD, generally, an analog signal output from the CCD is converted into a digital signal. Then sub-sampling is performed when processing the digital signal, thereby producing an image of a desired (lower) resolution.
In this case, however, the output of the CCD is inefficiently wasted, and noise is introduced due to the use of the memory, thus degrading the quality of the image.
In addition, there is a method of varying the resolution of the output image by a partial readout operation in which a part of the analog signal output from the CCD is selected, converted into a digital signal and processed.
In this case, however, only a part of the maximum number of valid pixels is used, and thus electric charges that are photoelectrically converted by the CCD are inefficiently wasted.